Pressure regulator construction

ABSTRACT

This disclosure relates to a pressure regulator formed from a one-piece flexible diaphragm and valve member structure wherein the flexible valve member is disposed spaced from one side of the flexible diaphragm so that the flexible valve member can be flexed through a valve seat of a housing to open and close the valve seat on one side thereof while the flexible diaphragm is disposed on the other side of the valve seat and can be utilized to cooperate with the housing structure carrying the valve seat to define a chamber therewith.

United States Patent Qaparone et al.

[ Mar. 14, 1972 PRESSURE REGULATOR CONSTRUCTION Michael J. Caparone,Arcadia; Theodore J. Dykmeul, Rolling Hills, both of Calif.

Inventors:

Assignee: Rohertshaw Controls Company,

Richmond, Va.

Filed: Apr. 21, 1970 Appl. No.: 30,551

Related US. Application Data Division of Ser. No. 752,403, May 6, 1968,Pat. No. 3,508,708, which is a division of Ser. No. 353,924, Mar. 23,1964, Pat. No. 3,439,699.

US. Cl 137/505.41l Int. Cl ..Fl6k 31/1145 Field of Search 1 37/66,505.41, 505.42, 454.6;

[56] References Cited UNITED STATES PATENTS 2,737,201 3/1956 St.Clair................ .....137/505.41 2,904,068 9/1959 St. Clair... 137/5054! 2,936,595 5/1960 Dillman ...137/505.4l X 3,043,332 7/1962Henriques.... ...137/505.l2 X 3,276,470 10/1966 Griffing ..137/505.4l X

Primary Examiner-Harold W. Weakley Attorney-Auzville Jackson, Jr.,Robert L. Marben and Candor, Candor & Tassone [5 7] ABSTRACT Thisdisclosure relates to a pressure regulator formed from a one-pieceflexible diaphragm and valve member structure wherein the flexible valvemember is disposed spaced from one side of the flexible diaphragm sothat the flexible valve member can be flexed through a valve seat of ahousing to open and close the valve seat on one side thereof while theflexible diaphragm is disposed on the other side of the valve seat andcan be utilized to cooperate with the housing structure carrying thevalve seat to define a chamber therewith.

5 Claims, 6 Drawing Figures PATENTEDMAR 14 I972 3,648,726

sum 1 {IF 2 FIG.4

INVENTORS MICHAEL J. CAPARONE THEODORE J, DYKZEUL ATTORNEYS PATENTEDMAR14 I972 3,648,726

' sum 2 OF 2 FIGS INVENTORS MICHAEL J. CAPARONE THEODORE J. DYKZEULATTORNEYS PRESSURE REGULATOR CONSTRUCTION This application is adivisional patent application of its copending parent application, Ser.No, 752,403, filed May 6, I968, now US. Pat. No. 3,508,708, which, inturn, is a divisional patent application of its copending parentapplication, Ser. No. 353,924, filed Mar. 23, l964, now US. Pat. No.3,439,699, and is assignedto the same assignee to whom the parentapplication is assigned.

This invention relates to an improved pressure regulator means or thelike as well as to improved parts for and method of making such apressure regulator means or the like.

Heretofore, various control devices have been provided for domesticwater heater tanks and the like to control the heating thereof.

For example, one such prior known control device includes a housingmeans to receive fuel, such as gas or the like, from the source thereof,and having means to selectively direct the fuel into a pilot burnermeans and a main burner means, the pilot burner means having acontinuously burning flame for lgniting fuel issuing from the mainburner means in an intermit tent operation thereof and the main burnermeans being utilized to heat the water in the tank to tend to maintainthe water at a constant temperature regardless of the amount of heatedwater drawn from the tank.

Such a prior known control device has a thermostatically operated valvemeans interconnecting the source of fuel with the main burner meanswhereby the thermostatic means senses the temperature of the water inthe tank and opens the valve means when the temperature of the waterfalls below a selected temperature to cause the main burner means toheat the water tank up to the selected temperature whereby thethermostatic means closes the valve means to terminate the operation ofthe main burner means.

However, it has been found that in such a prior known control device,not only must a separate adjustment be made on a pressure regulatingmeans of the control device to effect proper flame characteristic of thepilot burner means, but also a separate adjustment must be made on theC-valve or gas cock to select the proper burner input for a variouscapacity appliance.

According to the teachings of this invention, however, a separatepressure regulator is provided for the pilot burner means wherebyinitial adjustment of the pressure regulator will permit the fuel toissue from the pilot burner means at a substantially constant rateregardless of variations in the input pressure of the fuel as well asthe intermittent operation of the main burner means.

Thus, when the pilot burner pressure regulator of this invention isutilized in combination with a separate pressure regulator for the mainburner means, the need for either the pilot or main burner C-valveadjustment, other than proper orificing of the pilot and main burnermeans for the various capacities at the set regulated gas pressures, areeliminated. The elimination of these commonly required adjustments is aconvenience of commercial importance both to the appliance manufacturerand the user.

Thus, it can be seen that the pilot gas pressure regulator of thisinvention replaces the pilot adjusting key of prior known controldevices.

Further, the pressure regulator means of this invention is soconstructed and arranged that the same can be simply and effectivelyassembled to the desired control device in a unique manner hereinafterdescribed whereby the overall cost of the same is relatively small whencompared with other prior known pilot burner pressure regulators.

Accordingly, it is an object of this invention to provide an improvedpressure regulator having one or more of the novel features set forthabove or hereinafter shown or described.

Another object of this invention is to provide improved parts for such apressure regulator or the like.

A further object of this invention is to provide an improved method formaking such a pressure regulator or the like.

Other objects, uses and advantages of this invention are apparent from areading of this description which proceeds with reference to theaccompanying drawings forming a part thereof and wherein:

FIG. l is a broken-away, fragmentary, perspective view illustrating theimproved control device of this invention in combination with a waterheater tank or the like.

FIG. 2 is a fragmentary, cross-sectional view taken substantially online 2-2 of FIG. ll.

FIG. 3 is an enlarged, partially broken-away, front view of the controldevice illustrated in FIG. I.

FIG. 4 is a cross-sectional view of thecontrol device illustrated inFIG. 3 and is taken on line 4-4 thereof.

FIG. 5 is an enlarged, exploded perspective view of the pressureregulator of this invention.

FIG. 6 is an enlarged, fragmentary, cross-sectional view takensubstantially on line 6-6 of FIG. 3.

While the various features of this invention are hereinafter describedand illustrated as being particularly adaptable for forming a pressureregulator for the pilot burner means of a control device for a domesticwater heater tank or the like, it is to be understood that the variousfeatures of this invention can be utilized singly or in any combinationthereof to provide other constructions as desired.

Therefore, this invention is not to be limited to only the embodimentillustrated in the drawings, because the drawings are merely utilized toillustrate one of the wide variety of uses of this invention.

Referring now to FIGS. l and 2,. the improved control device of thisinvention is generally indicated by the reference numeral 20 and isadapted to maintain the temperature of the water contained in a waterheater tank 21 at a selected .temperature regardless of the amount ofhot water drawn therefrom, the water level in the tank 21 beingmaintained at a substantially constant level by conventional means (notshown) as hot water is drawn from the tank 21.

In particular, the control device 20 is interconnected to a source offuel by an inlet conduit 22 and is adapted to interconnect the inletconduit 22 to an outlet conduit 23 leading to a main burner means 24 forheating the tank 21. The control device 20 is also adapted tointerconnect the inlet conduit 22 to an outlet conduit 25 leading to apilot burner means 26 utilized to ignite fuel issuing from the mainburner means 24 in a manner hereinafter described.

A general operation of the control device 20 will now be described andreference is made to FIGS. 3 and 4.

When the water heater system of this invention is initially installed, acontrol knob 27 of the control device 20 is normally disposed in an offposition thereof, whereby a cock valve 28 disposed in the housing 29 ofthe control device 20 is disposed in such a position that communicationbetween a chamber 30 of the housing 29 and a pair of passages 31 and 32,respectively leading to the conduits 25 and 23 in a manner hereinafterdescribed, is prevented.

The chamber 30 of the housing 29 is separated from an inlet chamber 33by an annular valve seat 34, the inlet chamber 33 being in directcommunication with the fuel inlet conduit 22.

A valve member 35, carried on a rod or shaft 36, is normally seatedagainst the valve seat 34 by a spring 37 to prevent communicationbetween the chambers 30 and 33, the rod 36 being adapted to be pusheddownwardly to open the valve seat 34 by a button type plunger38. Theother end of the rod 36 is interconnected to suitable structure, (notshown) which will hold the valve member 35 in the open position asillustrated in FIG. 3 as long as a sensing member 39, F IG. 1, senses aflame at the pilot burner means 26.

However, should the flame at the pilot burner means 26 be extinguished,the valve member 36 is returned to the closed position thereof in aconventional manner to prevent communication between the chambers 33 and30 so that fuelgcannot issue from the main burner means 24 as well asthe pilot burner means 26 when no flame exists at the pilot burner means26 to ignite the main burner means 24.

To actuate the water heater system of this invention, the control knob26 is first rotated to a pilot" position thereof whereby fuel is adaptedto flow from the chamber 30 into a passage 40 leading to a passage 41that is interconnected to the passage 31 by a groove 42 in the gas cock28 in the manner illustrated in FIG. 3, the gas cock 28 only beingadapted to interconnect the chamber 30 with the pilot passage 31 and notwith the main burner passage 32 when the control knob 27 is disposed inthe pilot" position thereof.

With the control knob 27 disposed in the pilot" position thereof, thebutton 38 is manually pressed downwardly to manually open the valvemember 35 whereby fuel can issue from the pilot burner means 26 and beignited either manually or automatically as desired.

When a flame appears at the pilot burner means 26, the sensing means 39senses the flame at the pilot burner means 26 and maintains the valvemember 35 in the open position as illustrated in FIG. 3.

After the pilot burner means 26 has been ignited and the valve member 35is held in the open position thereof, the control knob 27 is rotated tothe ON" position thereof as illustrated in FIG. 3 whereby a passage 43of the gas cock 28 interconnects the chamber 30 with the passage 32leading to the main burner means 24 in a manner hereinafter described.

In the particular embodiment of the control device 20 of this inventionillustrated in the drawings, a pressure regulator 44, FIG. 4, isprovided for the main burner means 24 and will now be described.However, it is to be understood that the various features of thisinvention can be utilized without the pressure regulator 44 for the mainburner means 24, as desired.

As illustrated in FIG. 4, the housing 29 of the control device 20 isformed of two end housing sections 45 and 46 and a central housingsection 47 suitably bolted together in a manner conventional in the art.

The passage 32 leading from the gas cock 28 is formed in the housingsections 46 and 47 and communicates with an annular valve seat 48 formedin the housing section 47, the valve seat 48 leading to a compartment 49formed in the housing sections 45 and 47.

The compartment 49 of the housing 29 is divided into two chambers 50 and51 by a flexible diaphragm 52 secured between the housing sections 45and 47, the diaphragm 52 carrying a valve member 53 cooperating with thevalve seat 48 to control the flow of fuel from the passage 32 into thechamber 50.

The valve member 53 is normally urged to the open position thereof by alever 54 spring biased to the right by any of the means fully set forthin the copending patent application, Ser. No. 862,694, filed Dec. 29,1959, and entitled control devices," now abandoned.

In this manner, the pressure of the fuel flowing through the chamber 50of the housing 29 is regulated by the pressure regulator 44, the settingof the pressure regulator 44 being manual or automatic in any of themanners set forth in the aforementioned copending patent application.

The passage 55 leads from the chamber 50 to an annular valve seat 56formed in the housing section 47, the annular valve seat 56 leading toan outlet passage 57 adapted to be interconnected to the outlet conduit23 previously described and leading to the main burner means 24.

l A valve member 58 is carried by the housing 29 and is adapted tocooperate with the valve seat 56 to control the flow of fuel to the mainburner means 24.

The fuel is only adapted to pass through the valve means 58 in a mannerhereinafter described when a water temperature sensing meansfor athermostat 59, FIGS. 2 and 4, determines that the temperature of thewater in the tank 21 has fallen below a temperature selected by acontrol means 60 disposed in an openable compartment of the controldevice 20.

The temperature sensing or thermostat means 59 comprises a conventionaltube 61 and rod 62 arrangement, the tube 61 and rod 62 being disposed inthe interior of the tank 21 in such a manner that the end 63 of the tube61 is fixed relative to the tank 21 and the other end 64 thereof is freefor movement relative to the tank 21.

The rod 62 has an end 65 secured to the free end 64 of the tube 61 andis formed of a material having a lower coefficient thermal expansionthan the tube 61 whereby the free end 66 of the rod 62 is moved to theleft as illustrated in FIG. 4 when there is a decrease in temperature ofthe tank 21 because the tube 61 contracts. Conversely, the end 66 of therod 62 is moved to the right as illustrated in FIG. 4 when thetemperature in the tank 21 increases because the tube 61 expands.

In this manner, the thermostatic means 59, after the pilot burner means26 has been ignited and the control knob 27 is disposed in the onposition thereof, opens the valve means 58 in a manner fully describedin the aforementioned copending patent application to allow fuel toissue to the main burner means 24 when the temperature of the water inthe tank 21 has fallen below a selected temperature so that the mainburner means 24 will heat the water in the tank 21 to the temperatureselected by the control means 60 in a manner conventional in the art.

When the temperature of the water in the tank 21 has reached the desiredtemperature level, the thermostatic means 59 permits the valve means 58to close so that no fuel issues from the main burner means 24 until thetemperature of the water in the tank 21 falls below the selectedtemperature.

Thus, it can be seen that the main burner means 24 is intermittentlyoperated by the thermostatic means 59 to maintain the water in the tank21 at a selected temperature regardless of the amount of hot water drawnfrom the tank 21, the fuel issuing to the main burner means 24 beingmaintained at a substantially constant rate by the pressure regulator 44in the manner fully described in the aforementioned copending patentapplication.

While one type of general control system for heating the water tank hasbeen described, it is to be understood that such a system is merelyemblematic of the many different types of systems to which the followingfeatures of this invention can be utilized.

The particular details of the control device 20 will now be described inconnection with the separate pressure regulation of the flow of gas tothe pilot burner means 26.

As illustrated in FIG. 3, the pilot flow passage 21 is interconnected toa chamber 67 formed in the housing 29 and having a suitable filter means68 disposed therein.

In this manner, fuel flows from the passage 31 into the chamber 67 andthrough the filter means 68 to a passage 69 leading to an inlet passage70 formed in the housing 29 as illustrated in FIG. 6.

The inlet passage 70 interrupts a surface 71 of the housing section 46and is interconnected with a cavity 72 defined between the housingsections 46 and 47, the cavity 72 in the housing section 46 receiving apressure regulator 73 of this invention.

The housing section 46 is provided with a passage means 74interconnected with the chamber 72 to the left of the surface 71 for apurpose hereinafter described, the passage 74 terminating at an outletport 75 which is adapted to be interconnected to the outlet conduit 25leading to the pilot burner means 26.

Thus, it can be seen that the fuel flowing from the inlet conduit 22 tothe pilot burner means 26 must first pass through the pressure regulator73 of this invention whereby the pressure regulator 73 maintains thefuel flowing to the pilot burner means 26 at a substantially constantpressure regardless of the pressure regulation of the fuel flowingthrough the main burner means 24.

Further, it can be seen that the pressure regulation of the pilot burnermeaaans 26 is independent of the fluctuations of the input gas pressureas well as of the operation and pressure regulation of the main burnermeans 24.

The pressure regulator 73 as illustrated in FIGS. 5 and 6 comprises aflexible diaphragm 76 having an outer peripheral edge 77 terminating inan outwardly directed annular bead '76 extending from the side 79 of thediaphragm 76.

The diaphragm has a postlike member 66 integral therewith and extendingbeyond the opposed sides 79 and 611 of the diaphragm 76, the postlikemember 66 having a free end defining a valve member 62 in a mannerhereinafter described. The other end 63 of the postlike member 66 isinterrupted by a bore 6 1', and has an annular recess 65 formed thereinadjacent the side 61 of the diaphragm 76 for a purpose hereinafterdescribed.

An annular rib means 66 extends outwardly from the side 79 of thediaphragm 76 and is concentric with the postlike member 66. Radial ribs67 integrally interconnect the postlike member 66 with the annularreinforcing rib 66 as illustrated in the drawings.

In order to obtain flexibility of the diaphragm 76, the diaphragm 76 isprovided with an arcuate annular portion 162 as illustrated in thedrawings.

A metallic cup-shaped member 66 is provided for the pressure regulator73 and has an outwardly directed annular flange 69 at the open endthereof. In addition, the cup-shaped member 66 has an annular recess 96provided in the closed end thereof and disposed concentrically around avent opening 91 formed in the closed end thereof.

When it is desired to assemble the pressure regulator 73 of thisinvention in the control device 26 previously described, the housingmember 16 is utilized before the housing members 65 and 47 are assembledthereto.

A washerlilte member 92 is inserted into the cavity 72 of the housingmember 416 and is disposed against the annular shoulder 71 of thehousing 46 in the position illustrated in FIG. 6 whereby the housing 66can be staked over the washerlike member 92 at 93 to hold the washerlikemember 92 in place so that the washerlike member 92 can provide a valveseat 96 interconnecting the inlet portion 69 of the housing 66 with theoutlet portion 74 thereof for a purpose hereinafter described.

Thereafter, the flexible diaphragm 76 is disposed in the cavity 72 ofthe housing 66 in such a manner that the outer peripheral portion 77thereof is disposed against an annular shoulder 95 of the housing 36 andhas the peripheral bead 76 thereof received in an annular recess 96formed in the shoulder 95 in the manner illustrated in FIG. 6. Since thepostlilte member 66 and valve member 62 of the diaphragm 76 areflexible, the same are adapted to be flexed through the valve seat 96into the position illustrated in FIG. 6 whereby the valve member 62 isdisposed on one side of the valve seat 96 and the remainder of thediaphragm 76 is disposed on the other side thereof.

Subsequently, the cup-shaped member 66 is disposed in the cavity 72 ofthe housing 66 and has the annular flange 69 thereof disposed againstthe peripheral portion 77 of the diaphragm 76 to hold the same againstthe shoulder 95 of the housing 66.

In the manner, the cup-shaped member 66 cooperates with the flexed side66 of the flexible diaphragm 76 to define a chamber 97 therebetween.

Before the cup-shaped member 66 is disposed in the position illustratedin FIG. 6, a compression spring 96 has one end 99 thereof snapped overthe left hand end of the postlike member 66 of the diaphragm 76 so thatthe same is received in the annular recess 65 of the postlike member 66in the position illustrated in FIG. 6. Thus, when the cup-shaped member66 is subsequently disposed in the position illustrated in FIG. 6, theother end 166 of the barrel-shaped compression spring 96 is received inthe annular recess 96 of the cup-shaped member 66 whereby the force ofthe compression spring 96 acting between the cup-shaped member 66 andthe diaphragm 76 tends to move the diaphragm 76 to the right to causethe valve member 62 to open the valve seat 96 for a purpose hereinafterdescribed.

In order to hold the cup-shaped member 66 in the position illustrated inFIG. 6, the housing 66 is staked over at 1161 to hold the cup-shapedmember 66 and flexible diaphragm 76 in stacked relation against theannular shoulder of the housing 66.

Therefore, it can be seen that it is a relatively simple operation toassemble the pressure regulator means 73 of this invention in thehousing 66 of the control device 26 for the purpose previouslydescribed.

Should it be desired to adjust the force of the compression spring 96tending to open the valve member 62, the cupshaped member 66 is made ofsufficiently deformable material so that the closed end thereof can beinwardly deformed in the manner illustrated by dotted lines in FIG. 6 toincrease the force of the compression spring 96. Similarly, the closedend of the diaphragm of the cup-shaped member 66 can be deformedoutwardly beyond the full line position thereof to decrease the force ofthe compression spring 96 in order to effectively adjust the pressureregulator 73 to the desired value thereof.

The chamber 97 of the pressure regulator 73 is vented to the atmosphereby the vent opening 91 in the cup-shaped member 66 and suitable passagemeans in the control device 26 as illustrated in FIG. 6.

The operation of the pressure regulator 73 will now be described.

When fuel is adapted to flow through the passage means 69 by the cockvalve 26 in the manner previously described, the fuel flows through theopened valve seat 94, the valve seat 94 being opened by the compressionspring 98, and is adapted to flow against the side 79 of the diaphragmmeans 76 to be subsequently conveyed out through the outlet passagemeans 76 to the pilot burner means 26 for the purpose previouslydescribed.

However, should the pressure of the fluid acting against the side 79 ofthe diaphragm 76 exceed the force of the compression spring 96, it canbe seen that the diaphragm 76 will be moved toward the left whereby thepostlike member 66 will cause the valve member 62 to progressively movetoward the valve seat 96 to close the same whereby the pressure valve ofthe fluid passing through the outlet passage means 74 to the pilotburner means 26 will be maintained at a constant pres sure regardless ofthe input pressure of the fluid or the pressure regulation of the fluidflowing to the main burner means 24 for the reasons previouslydescribed.

Accordingly, it can be seen that not only does this invention provide animproved pressure regulator having many novel features, but also thisinvention provides improved parts for and methods of making such apressure regulator or the like.

What is claimed is:

l. A device for controlling the flow of fluid comprising a housinghaving an inlet means adapted to be interconnected to a source of fluid,said housing having a passage means interconnected to said inlet means,and a pressure regulator being defined in part by said housing and beingdisposed in said passage means to maintain a flow of fluid at asubstantially constant rate, said housing having a surface meansinterrupted by an inlet interconnected to the inlet side of said passagemeans and by an outlet interconnected to the outlet side of said passagemeans in spaced relation thereto, said surface means also beinginterrupted by a recess that defines an annular shoulder surroundingsaid inlet and said outlet, said pressure regulator having a flexiblediaphragm carrying a valve member for opening and closing said inlet ofsaid passage means, said pressure regulator having a cup-shaped casingmember provided with an annular fllange at the open end thereof that isreceived in said recess for holding said flexible diaphragm in sealedrelation against said annular shoulder of said surface means of saidhousing outboard of and surrounding said inlet and outlet of saidpassage means to define a chamber between said diaphragm and saidsurface means that is adapted to be in fluid communication with saidinlet and said outlet of said passage means, said cup-shaped casingmember being a one-piece structure and having the closed end thereofbeing centrally recessed to define an annular spring retaining groove insaid cup-shaped casing member, said closed end being flat inboard of andspanning said annular groove and being centrally interrupted by anopening passing therethrough, said casing member and said diaphragmdefining another chamber therebetween which is vented to the exterior ofsaid casing member by said opening thereof, and a compression springdisposed in said other'chamber between said groove and said diaphragm totend to move said valve member in one direction relative to said inlet.

2. A device as set forth in claim 1 wherein said cup-shaped casingmember is secured to said surface means of said hous-

1. A device for controlling the flow of fluid comprising a housinghaving an inlet means adapted to be interconnected to a source of fluid,said housing having a passage means interconnected to said inlet means,and a pressure regulator being defined in part by said housing and beingdisposed in said passage means to maintain a flow of fluid at asubstantially constant rate, said housing having a surface meansinterrupted by an inlet interconnected to the inlet side of said passagemeans and by an outlet interconnected to the outlet side of said passagemeans in spaced relation thereto, said surface means also beinginterrupted by a recess that defines an annular shoulder surroundingsaid inlet and said outlet, said pressure regulator having a flexiblediaphragm carrying a valve member for opening and closing said inlet ofsaid passage means, said pressure regulator having a cup-shaped casingmember provided with an annular flange at the open end thereof that isreceived in said recess for holding said flexible diaphragm in sealedrelation against said annular shoulder of said surface means of saidhousing outboard of and surrounding said inlet and outlet of saidpassage means to define a chamber between said diaphragm and saidsurface means that is adapted to be in fluid communication with saidinlet and said outlet of said passage means, said cup-shaped casingmember being a one-piece structure and having the closed end thereofbeing centrally recessed to define an annular spring retaining groove insaid cup-shaped casing member, said closed end being flat inboard of andspanning said annular groove and being centrally interrupted by anopening passing therethrough, said casing member and said diaphragmdefining another chamber therebetween which is vented to the exterior ofsaid casing member by said opening thereof, and a compression springdisposed in said other chamber between said groove and said diaphragm totend to move said valve member in one direction relative to said inlet.2. A device as set forth in claim 1 wherein said cup-shaped casingmember is secured to said surface means of said housing by a stakingarrangement thereof.
 3. A device as set forth in claim 2 wherein saidstaking arrangement comprises part of said housing being staked oversaid cup-shaped casing to hold said cup-shaped casing and diaphragmbetween said housing part and said surface means.
 4. A device as setforth in claim 1 wherein said part of said housing is staked over saidannular flange of said cup-shaped casing.
 5. A device as set forth inclaim 4 wherein said annular flange is outwardly directed relative tosaid open end.